1. Technical Field
The present disclosure relates to knotless tissue and suture anchors and, more particularly to radially expandable anchors and methods for use of the expandable anchors.
2. Background of Related Art
During surgery it is often necessary to attach prosthetic implants or soft tissue such as muscle tissue, ligaments, or tendons to hard tissue such as bone. Various types of surgical fasteners are employed for accomplishing this function, including staples, screw and washer systems, suture anchoring devices, and tissue anchors.
The first of these types is illustrated in U.S. Pat. Nos. 4,454,875 and 4,570,623, which show metal staples with spikes on the underside of the crosspiece to secure ligaments.
Fasteners included in the second of these types are available as screw-washer combinations wherein the screw is fabricated from a surgically suitable metal, such as titanium or stainless steel alloy, and is usually of self-tapping design. Suture anchors are adapted to be inserted into predrilled holes in bone and can be made of bioabsorbable material. When securing a ligament or suture within a bore drilled in bone, the self-tapping screws may abrade the ligament or suture as they are threaded in.
Suture anchors are also used to draw tissue adjacent bone. The anchor, having a first end and a suture attached thereto is anchored in bone and a second end of the suture is threaded through tissue and a knot is tied to secure the tissue to the bone.
Expandable tissue fasteners adapted for use in minimally invasive surgical procedures (e.g. arthroscopic procedures) are employed, for example, in the repair of shoulder and knee injuries. In such procedures, the operating instrumentation is usually deployed through a long, narrow cannula inserted through a small incision in the skin. Knots in the suture are typically tied remotely and pushed down to the anchor to secure the tissue and the site.
What is needed is an expandable tissue fastener or anchor for knotlessly securing tissue bone, and for atraumatically securing a graft to bone, especially in minimally invasive surgical procedures.